Use leisure=resort to mark territory of the resort. Such areas contains entertainment (like water slides, dance floors etc), sport (ski slopes, tennis courts etc), health (natural mineral water springs, mud baths) and/or other recreation infrastructure (fishing ponds, beaches, restraunts) and provides housing for customers. They are also usually operated by single company.

The main difference from areas tagged as tourism=hotel is that resorts sells their recreation services and housing as an additional service. While hotels sells its housing services and recreation is just an additional service. You can also tag as tourism=hotel or tourism=chalet parts of leisure=resort that contains housing infrastructure only.